I have an interesting experience to share with you PC geeks/tweaker types.
A quick background. I have a circa 2007 Toshiba laptop running 32 Bit Vista, with a AMD Turion X2 TL-64 processor and 4 GB of ram, which I use daily for my computing needs.
It does alright for a circa 2007 Laptop, but I've done a few things to really pep it up over the years. The first thing I did when I started down this path was to 'max out' the ram to 4 GB (it came with just 2 GB when I bought it), which is when I discovered that the system can normally only assign addresses 4 GB of stuff, and some of those addresses going to my integrated video as well as other hardware/software items. So I only have 3309 MB of 'accessable' memory on my system. BTW, the amount of 'available ram' left over when 4 GB+ is installed that you will have in a 32 bit windows environment will vary from system to system, based on what addresses your system needs to set aside for other things. Also, why I said 4GB+ and not just 4GB just now is explained below.
Disclaimer: if you aren't comfortable with tweaking/upgrading your system, or aren't willing to risk the consequences if you do something wrong, bail out now!
A little over a year ago, I also installed a 750 GB 7200 RPM Seagate Hybrid Drive with an 8 GB 'SSD' built in. This really gave me a nice performance boost, noticably above what a 'normal' 7200 RPM drive will give you, but that 8 GB of fast storage only goes so far, and I have no control over it - the Seagate driver optimizes what is stored there based on what the system uses most. Nonetheless, with only one active hard drive bay, this can be a useful upgrade if you are looking for a decently priced large storage option for your laptop or other system with only one HDD bay available, that performs well. I consider it money very well spent!
BTW, I actually do have a empty second HDD bay in this laptop, which is why I picked this laptop in the hopes of adding a second HHD later, which as it turns out is missing the necessary internal connectors. Toshiba didn't bother to include a second HDD interface on my 'retail' model, so short of buying a used connector and installing it myself, and risking damage to the system, no dice.
I've also done the appropriate system file tweaks to make my ram above 2GB more accessable (the 3GB tweak), which has helped with one of my games in particular, and perhaps some of my other programs.
More recently, I installed a DataRAM Ramdisk utility, which I sized at 256MB. I've worked with RamDisks before, and use this to cache temporary internet files. Again, for internet browsing this helps A LOT, with Mozilla windows/tabs opening MUCH more quickly than they did before, especially when I revisit verious webpages..
Anyways, on the RamDisk that I set up many months ago now, I'm only using around 82 MB currently of that 256 MB for such temporary caching, so I felt it was time to drop that number to, say, 128 MB. Well, the widget has a field to change the RamDisk size, which is 'locked' currently, even when I disable the ramdisk to try to change it. While doing research to try to figure out how to 'unlock' this so I could free up another 128 MB of ram for app usage, I came across some articles which mentioned that a couple of RamDISK utilities in particular included a feature to access my 'hidden' ram. One of these had an 80 dollar price tag, which for that price I could instead have just bought a 4GB memory stick and then set up a 2GB ramdisk with the 2GB of 'extra' memory... As I'm looking to just get a new 64 bit laptop soon, I wanted to go with a cheaper/free option in the interim.
BTW, according to Microsoft, it is possible to access your memory above 4 GB in various 32 bit Windows versions if you make some changes to BCDEdit which involve your DEP and PAE settings. Essentially you'd presumably would set up a ram disk with your 'excess' memory, but by itself you can't access that 'lost' memory where the 32 Bit OS assigns the memory addresses elsewhere. Also, some have noted that using PAE caused instability in their case, so I was of course apprehensive.
Anyways, after playing with the PAE settings with no success, and having seen a few mentions of Gavotte RamDisk, I decided to give it a crack. I followed this very nice guide, written by Jen Scheffler.
These articles usually come with a comment section, the most prominent of which is 'Windows can only address 4 GB of memory with 32 Bit, this won't work, you need the 64 Bit version of Windows'.
Long story short, I now have an R drive that is 783 MB in size, using my 'hidden' memory. My memory widget shows the same 44% usage as before, and 3309 MB of system memory, as it did before, with the same roughly 44% or so memory usage when doing my internet rounds, that I had been seeing before adding the Gavotte utility. The Gavotte utility doesn't cache data to the disk like the DataRAM does (at least not that I've figured out), but as it turns out, as the author above suggested, it works AWESOMELY for a 'Paging/Swap' file.
BTW, my NX is now set to OptOut, and PAE is currently set to ForceEnable, which incidentally activated my 'DEP' options in my System Properties (they were grayed out before). Again, I'm using Vista 32 Bit Home Premium. NX is your DEP/Protected Memory feature, so it's kind of important to have... Also, you MUST have a 64 Bit capable system, which in my case I do. My laptop had a Vista 64 bit option from Toshiba, so I wasn't worried on this front.
Normally, it makes almost NO sense to assign a paging file to memory in most situations, as you are better off just using the memory as memory, so you don't need to 'swap out' that stuff from memory in the first place. HOWEVER, in this case, this is memory I could otherwise NOT use as system memory, so in this particular instance it is useful. BTW, my 'main/larger' paging file sits on my 'E' partition, if anyone cares.
Sooo, how has this worked out? Well, my system is even more snappy now, webpages (assuming they've been previously cached to the temp files) are opening in fractions of a second in many cases (the 4G internet I have also helps), and even Photoshop seems peppier to me. My system is behaving VERY smoothly now, and this would ALMOST prevent me from doing the expensive laptop upgrade I have planned later this year. BTW, based on my quick search of the Microsoft database, Vista chooses how to assign items to the Swap files if you have set up more than one, based on which drive is the least busy, so in this case it seems to be choosing very wisely, based on the near breakneck response speeds I'm now seeing that I wasn't seeing before doing this.
Note that I use 'temporary' data for both of my Ram Drives, which incidentally are currently existing peacefully alongide each other, as you lose the data stored in the RamDisk memory, HDD cache aside, when you shut down your system or have a hard crash. I could theoretically install programs to the DataRAM disk, but haven't felt the need.
For most people, who are now using 64 bit Windows systems, this won't be useful to you, but for those of us still in the dark ages of 32 bit windows systems which have 64 bit capability, and with that 'hidden' unaccessable memory, I thought this might be of interest to you!
2nd Disclaimer: Again, tweaking your system settings can in some instances cause instability and in some cases system/OS failure. If you are faint of heart, don't do it, and of course backing up things beforehand is always good advice!